Disconnecting Stations From The Profibus - Siemens SINUMERIK 840D sl Manual

Wiring the bus connector
1. Proceed as follows to connect the bus connector:
2. Plug the bus connector into the corresponding interface on the control unit.
3. Screw the bus connector into place.
Figure 9-5
9.7.6

Disconnecting stations from the PROFIBUS

Removing the bus connector
You can remove the bus connector with a looped-through bus cable from the PROFIBUS DP
interface at any time without interrupting data traffic on the bus.
Data exchange on the bus can be interrupted!
A bus segment must always be terminated with the terminating resistor at both ends. This
is not the case, for example, if the last node with a bus connector is deenergized. Because
the bus connector takes its voltage from the node, this terminating resistor is ineffective.
Make sure that the nodes at which the terminating resistor is connected are always
energized.
NCU
Manual, 07/2007, 6FC5397-0AP10-2BA0
As the control unit is located at the start or end of a segment, you must switch on the
terminating resistor ("ON" switch setting).
Terminating resistor switched on and off
Note
Make sure that the stations on which the terminating resistor is located are always
supplied with voltage during booting and operation.
WARNING
Connections
9.7 PROFIBUS / MPI
85